Pressurized beverage dispensing systems, particularly for beer, have conventionally been arranged as shown in FIG. 1. Two or more barrels or other containers 10 have been connected to a common source 20 of a gas such as carbon dioxide to pressurize them, and the lines 12 conducting the beverage from the respective containers have been connected via a selection valve 14 to a single line 16 running from a remote storage area for the beverage containers to a single faucet or tap 18 for dispensing the beverage. In an alternate system known to the art each container has had an independent tap line running to an independent tap, with line valves for each tap line located in the container storage area.
It is desirable to dispense beverages sequentially from more than one container because more of the beverage can be dispensed from the tap without leaving the dispensing area, and because one container can be drawn at a time, avoiding the problem of waste due to spoilage of partially full containers. But the system previously described does not meet the first stated objective because each time a container is emptied one must go to the container storage area to operate valve 14, or a line valve, even though such a trip would not be necessary to tap new containers. This procedure is especially troublesome if the beverage storage area is remote from the bar. If only one bartender is attending the tap, he or she must leave the bar to shift valve 14. This system also does not provide a backup line in case line 16 becomes filled with air or gas, rendering it temporarily unusuable for dispensing a beverage such as beer.
Another problem with existing systems is that when more than one beverage is to be dispensed, separate lines 12, valves 14, lines 16 and taps 18 are provided for each beverage, but a single source of pressure such as a cylinder or pressurized gas commonly furnishes pressure to drive different beverages through their respective dispensing systems. The various beverages dispensed differ in their physical characteristics, particularly their density, their tendency to foam, and the amount of dissolved and entrained gas present in each. When each beverage is driven at a common pressure they dispense very differently at the taps so that a light beer may be dispensed as foamy "wild beer", while a stout may be dispensed quite slowly.